Update all the occurance of specific data from a Mongodb database using Node.js


What do we intend to make ?

In this Chapter , we will learn about updating all the occurances of the data matching our query in a mongoDb database using node.js

Let's Start !

Step - 1 : Including Packages
We will start by requiring the package. We are using the following package in our application :

		        

var mongo = require('mongodb');
                
	            


Step - 2 : Establish Connection
Now let's establish a connection between the mongoDb Database and our node.js application.

		        

var new_db = "mongodb://localhost:27017/demo_db"



                
	            

  • demo_db is the name of the database. You can change it as per your wish.
  • 27017 is the port where our mongoDb is running.
  • Localhost i.e. 127.0.0.1 is the local IP.

Step - 3 : Update all Occurances
updateMany() is the inbuilt method of mongodb which is used to search for the given query and update all its occurances.

Syntax
The syntax of the updateMany is :                

		        
db.collection("NAME_OF_THE_COLLECTION").updateMany(SEARCH_CONDITION , UPDATED_VALUE, (CALLBACK_FUNCTION) => {});
				
	            

Let's try it in our code block

		        
//updateMany-mongodb-nodejs.js
var mongo = require('mongodb');
var new_db = "mongodb://localhost:27017/demo_db"

mongo.connect(new_db ,(error , db) => {
	if (error){
		throw error;
	}
	
	//query store the search condition
	var query = { age : {$gt : "22" } };
	//data stores the updated value
	var data = { $set : {age : "above 22" } }
	//CREATING A COLLECTION IN MONGODB USING NODE.JS
	db.collection("details").updateMany(query , data, (err , collection) => {
		if(err) throw err;
		console.log(collection.result.nModified + " Record(s) updated successfully");	//It will console the number of rows updated
		console.log(collection);
		db.close();
	});
});


                
	            

You can run the above code using the following command :

		        

D:\nj-learn-mongo>node updateMany-mongodb-nodejs.js

				
	            

The output of the above code is :

		        

D:\nj-learn-mongo>node updateMany-mongodb-nodejs.js
3 Record(s) updated successfully
{ 	result: 
		{ 
			ok: 1,
			n: 3,
			nModified: 3 
		},
	connection: null,
	message: undefined,
	modifiedCount: 3,
	upsertedId: null,
	upsertedCount: 0,
	matchedCount: 3 
 }